Electric battery.



FFICE.

ROBERT E. HALL, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE WA- TERBURY BATTERY COMPANY, OF WATERBURY, CONNECTICUT.

' ELECTRIC BATTERY.

SPECIFICATION forming part of Letters Patent No. 665,679, dated January 8, 1901. Application filed December 15, 1899. Serial No. 74=O,4=58. (No model.)

To all whom, it may concern: In my improvementa glass jaris preferably Be it known that I, ROBERT E. HALL, acitiused; but it is not absolutely necessary, as zen of the United States, residing at Bridgewill be readily understood from the following port, in the county of Fairfield and State of description.

Connecticut, have invented certain new and I preferably utilize a box having two opuseful Improvements in Electric Batteries; posite perforated metal sides 1, and two opand I do hereby declare the following to be posite imperforate glass sides 2, and a zinc a full, clear, and exact description of the inring 3, suspended by aconductor-rod 4, which vention, such as will enable others skilled in latter is secured to the cover 5 of the jar and 10 the art to which it appertains to make and properly insulated therefrom. I also employ use the same. W a conductor-rod 6, which is connected with My invention relates to certain new and the metallic portion of the box and is secured useful improvements in electric batteries, but to the cover 5 and properly insulated theremore particularly relates to batteries of this from. Ordinary fastening contact devices '7 1 description which utilize oxid of copper, pref- 8 are used at the upper ends of these rods 4 6,

erably in the form of copper scale, and a causrespectively tic-alkali solution. In the drawings the jar is denoted by dotted The object of my invention is to provide a lines, and I employ any suitable caustic alconstruction in which the degree to which kalisuch as caustic sodain making the so- 20 the battery has been exhausted may be readily lution, which is poured within the jar. Since apparent to an unskilled person; and with the glass is a non-conductor and is impel-fothis end in view my invention consists in cerrate, the action of the solution upon the coptain details of construction and and combiper scale will be through the perforated metal nation of parts, such as will be hereinafter sides from the outside of the scale in parallel 2 fully set forth and then specifically be desigvertical planes, which gradually approach nated by the claim. each other as the scale is acted upon, and as In the accompanying drawings, which form fast as the solution acts upon the scale the e a part of thisapplication, Figures 1 and 2 latter will turn red, so that it will be readily are, respectively, elevations taken from difapparent through the glass sides 'whether or o ferent points of View of a battery constructed not there is any great amount of energy left in accordance with my improvement. Within the battery. For instance,when at the Similar numbers of reference denote like vertical center of one of the glass sides a conparts in both figures of the drawings. siderable amount of the scale appears unaf- In a battery of this description the copper fected by the solution it will be evidence that 3 5 scale has been held within aperforated basket, the battery has quite awhile to run, while, on

which latter is suspended Within the soluthe other hand, should the vertical red coltion, and as the scale is acted upon by the umns of the scale be quite close to each other,

solutionit will turn red, beginning at the leavingonlyanarrowvertical stripof the noroutside and working inwardly toward the mal scale apparent through the glass sides, 4o center, and it is therefore difficult for an unthis will be evidence that the battery will skilled observer to ascertain the amount of have to be renewed within a short time.

energy remaining in the battery. It has been The advantage in using a glass jar is that essayed to overcome this difficulty by using the observer may instantly determine withaglass jar containing a perforated cylinder out removing the box the actual condition 5 5 and by placing the copper scale between the of the battery; but glass jars are objected to jar and the cylinder; but this construction by many, especially railroad-men, on account will not readily ascertain the degree to which of their fragile nature, and therefore it frethe copper has been acted upon by the soluqnently becomes necessary to use jars made tion, and, moreover, this construction conof any suitable tough material. My improve- 10:: 5o templates, as a necessity, the use of a glass ment does not therefore contemplate as one jar and is, moreover, quite expensive. of its essential features the use of any particular kind of jar, and if an opaque jar be used it simply becomes necessary to raise the box slightly in order to determine the condition of the battery.

I have shown in the drawings a four-sided box, two of the opposite sides being glass; but it will be obvious that the structure so far as the glass is concerned may be considerably varied Without departing from the spirit of my invention. For instance, since the object of the perforated metal sides is simply to allow the solution to act upon the copper it will be clear that the box might be made entirely of glass, and in this case the box would be submerged an inch or twobelow the level of the solution, so that the lat ter would act upon the copper from the top, the result of this being that the reddish appearance would begin at the top and gradually extend toward the bottom of the box. Therefore I do not wish to be limited to the exact construction of this box shown; but 

